对于第 6 题至第 17 题，请在每道题提供的空白处清楚地写出解答过程，并将答案写在给定的空格内。每道题或每小题末尾括号 [ ] 内的数字表示该题的分数。对于需要单位的题目，请给出所要求的单位。

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一所学校正在为一次捐款活动筹集资金。学校中 $\frac{1}{2}$ 的学生捐款了 $3。其中 $\frac{2}{5}$ 的学生捐款了 $4。其余的学生捐款了 $5。该校共筹集到 $9000 的捐款。这所学校共有多少名学生？ 答：___

1. Find the fraction of students who donated $5.

Fraction of students who donated $5 =$1 - \frac{1}{2} - \frac{2}{5} = 1 - \frac{5}{10} - \frac{4}{10} = \frac{1}{10}$

2. Calculate the total donation collected from a hypothetical group of 10 students (1 unit of students).

Let the total number of students be $10$ units.
Number of students donating $3 = 5$ units.
Number of students donating $4 = 4$ units.
Number of students donating $5 = 1$ unit.
Total donation for $10$ units of students = $(5 \times \char36{}3) + (4 \times \char36{}4) + (1 \times \char36{}5) = \char36{}15 + \char36{}16 + \char36{}5 = \char36{}36$

3. Find the total number of students by comparing the hypothetical total donation to the actual total donation.

Number of groups of $10$ students = $9000 \div 36 = 250$
Total number of students = $250 \times 10 = 2500$